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Fencer Vulns
medium 6.5

CVE-2026-118174 json

Displaying a message could load an attacker-chosen URL through an OpenPGP key attachment

published 2026-10-27 12 d ago modified 2026-11-04 5 d ago also EUVD-2026-111351

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

When a message containing an OpenPGP key attachment was displayed, Thunderbird automatically loaded the attachment's content to offer importing the key. A sender could mark the attachment as an external attachment pointing to an arbitrary URL, which Thunderbird then loaded without any user interaction, bypassing remote content blocking. On Windows, a URL pointing to an attacker-controlled network share could leak the user's NTLM credentials. The NTLM credential leak only affects Thunderbird on Windows. On other operating systems, the issue allowed a remote request that bypassed remote content blocking. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.

Patch / fix

  • mozilla thunderbird 153.6, 159
  • mozilla thunderbird_esr 153.6, 159
  • thunderbird Debian 12 1:153.6.0esr-1~deb12u2
  • thunderbird Debian 13 1:153.6.0esr-1~deb13u1

debian advisories DEBIAN-CVE-2026-118174

  • MozillaThunderbird openSUSE Tumbleweed 153.6.0-1.1

opensuse advisories openSUSE-SU-2026:12339-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-118174 updated cvss 7.5

thunderbird: Displaying a message could load an attacker-chosen URL through an OpenPGP key attachment

  • Red Hat Enterprise Linux 8 thunderbird, thunderbird 140.17.0-1.el10_2 Red Hat Enterprise Linux 9 thunderbird, thunderbird 140.17.0-1.el10_2 Red Hat Enterprise Linux 10 thunderbird 140.17.0-1.el10_2
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

  • Mozilla Thunderbird

Classification

Weakness
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.